Bacterial meningitis

Question 1

What is meningitis?

Answer 1

Inflammation of the meninges of the brain typically as a result of an infective cause like bacterial, fungal, viral, or aseptic

Question 2

What are the main causative agents of bacterial meningitis specifically meningococcal meningitis?

Answer 2

Neisseria meningitidis

Streptococcus pneumoniae

Question 3

What types of meningitis are present and what is their mortality rate?

Answer 3

1. Pneumococcal meningitis= up to 20%

2. Meningococcal meningitis c. = 10%

Question 4

Describe the microbiology of Neisseria meningitidis?

Answer 4

Gram -ve diplococcus
Divided based on capsular group 
12 types 
Common= B, C, W, Y
A, B, and C are responsible for 90% of disease globally

Question 5

Where does Neisseria meningitidis inhabit?

Answer 5

Upper respiratory tract
Throat
Middle meatus

Question 6

Describe the initial colonisation of Neisseria meningitidis?

Answer 6

Nasopharyngeal carriage

Age , behaviour, and population are important factors in carriage

Question 7

How is Neisseria meningitidis transmitted?

Answer 7

Aerosol droplets

Question 8

What are the innate defense mechanism of the upper respiratory tract which prevent Neisseria meningitidis development?

Answer 8

1. Mucociliary pathway
2. Nitric oxide= produce antimicrobials
3. Colonisation resistance= bacteria already in nasal cavity, take up a lot of available nutrients so reduces competition
4. Lactoferrin

Question 9

What groups of people carry Meningococcal?

Answer 9

19-20 years

Question 10

Describe the carriage of Neisseria meningitidis?

Answer 10

Carriage in a healthy host exists before invasive infection

Facilitated by down regulation or loss of capsule expression

Question 11

If Neisseria meningitidis enters blood how does it survive?

Answer 11

Uses virulence factors
Expression of polysaccharide capsule- allows it survival in blood
Nm capsules inhibit opsonophagocytosis through charge
Capsule serotype B mimics host as it is identical to NCAM (neural cell adhesion molecule)
Eventually host is damaged following immune system activation- blebbing of cell wall
Uncontrolled growth in blood can lead to meningococcal septicaemia

Question 12

How does Neisseria meningitidis move across the blood brain barrier and cause infection?

Answer 12

If bacteria is present in hosts blood
Adheres to brain endothelial cells need for BBB crossing
Tight junction depletes
Paracellular movement occurs
Endotoxin produced and host inflammatory response after the migration of Polymorphonuclear neutrophils across BBB causes CNS injury
Infection of the meninges of the brain by Neisseria meningitidis = meningococcal meningitis

Question 13

What are the signs and symptoms of bacterial meningitis?

Answer 13

Non-blanching rash
stiff neck
altered mental status 
bulging fontanelle
photophobia

Question 14

What are the signs of septic shock which can be caused by bacterial meningitis?

Answer 14

1. Tachycardia
2. Breathing difficulty
3. Leg pain
4. Cold hands and feet
5. Altered mental state
6. Poor urine output

Question 15

What are the vaccination measures taken to prevent meningococcal meningitis?

Answer 15

8 weeks old= Men B vaccine= bexsero
16 weeks old= Men B vaccine
12 months old= HiB/Men C vaccine= menitorix and the Men B booster= bexsero
14 years old and eligible up to 25 years old= Men ACWY vaccine= nimenrex or Menveo

Question 16

What are the NICE guidelines for treating bacterial meningitis?

Answer 16

Transfer to secondary care as 999 emergency
Secondary care
 Antibiotic treatment promptly
Suspected bacterial meningitis
 3m+ of immediate IV ceftriaxone if 7 days confirmed meningococcal or 14 days confirmed Sp
 Less than 3m= cefotaxime + amoxicillin/ampicillin

Question 17

What does Streptococcus pneumoniae cause?

Answer 17

Pneumococcal meningitis and community acquired pneumonia

Question 18

Describe the microbiology of Streptococcus pneumoniae?

Answer 18

Gram +ve coccus
Non-motile
Has polysaccharide capsule

Question 19

What virulence factors does Streptococcus pneumoniae use to evade immune response?

Answer 19

polysaccharide capsule Neuraminidase= reduces viscosity of mucous
IgA protease= cleaves IgA

Question 20

What virulence factors does Streptococcus pneumoniae use to survive in the blood?

Answer 20

Polysaccharide capsule= the charge protects it from opsonophagocytosis as macrophage and the bacteria repel due to their charges
Massive activation of host cell complement and coagulation systems
Host cell mediated damage and Pneumolysin- allow and aid it to cross BBB
Neutrophil recruitment in CNS= leads to neurological sequelae

Question 21

Where does Streptococcus pneumoniae inhabit?

Answer 21

Nasal cavity
Nasopharynx
Pharynx

Question 22

What are the vaccination measures taken to prevent Streptococcus pneumoniae?

Answer 22

12 weeks old= PCV pneumococcal vaccine
12 months old= booster of the PCV
Eligible paediatric groups= live attenuated flu vaccine which is annual
65 years= PPV pneumococcal vaccine
65 years >= inactivated annual flu vaccine

Question 23

Describe the PCV vaccine in more detail?

Answer 23

Prevenar 13= pneumococcal conjugate vaccine (PCV)
13 valent conjugate vaccine used in 2 yrs. or younger
Valent conjugates= 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F
Increase in invasive disease is due to non-vaccine serotypes occurring

Question 24

How many serotypes does the PPV vaccine have?

Answer 24

23

Question 25

What other management is needed for Streptococcus pneumoniae?

Answer 25

IV antibiotics

Question 26

What is the role of a pharmacist in bacterial meningitis?

Answer 26

Raise symptom awareness
Public education
Awareness of vaccine schedule